Process of oxidizing ammonia and recovering acid as alkali-metal salts



atented June19, 1923. Q

FELICE BELIS A, OF GENOA, ITALY PROCESS OF OXIDIZING AMMONIA A'NlDRECOVERING ACID AS ALKALI-METAL SALTS.

Ho Drawing.

Application filed August so, 1920. Serial no. 407,036.

asman UNDER 'rrm PROVISIONS or THE ACT or MARCH 3, 1921, 41 STAT. I..,ma

To all whom it may concern:

Be it known that I, Fnmcn BENSA, manufacturer, subject of the Kingdom ofItaly, and resident of Genoa, Italy, have invented or discovered acertain new and useful Process of Oxidizing Ammonia and Recovering Acidas Alkali-Metal Salts (for which I have filed application in ItalyAugust 4, 1915; France July 29, 1916; England August 4, 191.6), of whichthe followingis acid various catalysts such as oxides of cop-- per ofiron and of the rare metals have been perature between 300 and 350. C.When a 1 used in association with platinized o'r palladiumized asbestos.Catalytic oxidation of ammonia has also been effected in the presence ofsteam. It has also been proposed to effect the absorption of thenitrogen oxides produced by the catalytic oxidation of ammonia in solidbases such as alkalis or alkaline earth hydrates or carbonates at a hi htemperature.

The process according to my invention consists in bringing a mixture ofsteam, hot ammoniacal gases and a considerable quanity of air into aretort maintained at a temperature of 600 to 800 (1., said retortcontaining a layer of platinized or palladium- 40 ized asbestos andseparate layers of oxide of copper, oxide of iron and oxides of rareearths, said layers being suitably arranged to cause the passage of saidmixture of gases through them successively, and passing said gases fromsaid retort'to receptacles containing alkaline carbonates, saidreceptacles being maintained at a. temperature of 2,00

The process is practised commercially as follows First, there areintroduced into a retort brought to a temperature of from 600 to 800 0.,hot ammoniacal gases mixed with steam together with a considerablequantity of air or oxygen. The said gases first/meet 55 in the retort alayer of platinized or palladiumized asbestos and, subsequently contactwith layers of iron and of oxides of rare earths, the copper oxide,etc., being arranged preferably in separate layers. p

The oxidation of the nitrogen takes place,

and the NOand NO combine with the steam i to produce nitric acid andnitrous acid.

The gases leaving the retort are led directly into receptacles ofrefractory ma- 5 terial containing solid alkaline carbonates. The saidreceptacles are disposed in series in such manner that the'gaseousmixture passes through the contents of the second receptacle afterhaving acted on the contents of the first.

The receptacles are maintained at a temthe mass is in a state of fusion,the operation is concluded and the product drawn off.

Having now particularly described and formed, I declare thatwhat' Iclaim is The herein described process of oxidizing ammonia andrecovering acid as alkalimetal salts, said process consistingin-subjecting a layer of metalized asbestos and separate layers of oxideof copper, oxide of iron, and oxides of rare earths to 'the action of amixture of steam, hot am moniacal gases and air in a retort maintainedat a temperature of from 600 to 800 (1, passing said mixture of gasesthrough said layers, and then passing said. gases to receptaclecontaining alkaline cars bfonates, said receptacles being maintaincd ata temperature of from 300 to'350 C.) Signed at Milan, Italy, this 1stday 0 may, A. D. we.

names BENSA.

